The fate of diurnal primates in southern Sumatra

Gibbon Journal Nr. 2 – 2006
18
The fate of diurnal primates in southern Sumatra
1
2
Thomas Geissmann , Vincent Nijman & Robert Dallmann
3
1
Anthropologisches Institut, Universität Zürich-Irchel, Switzerland
E-mail: [email protected]
Zoological Museum, University of Amsterdam, The Netherlands
3
Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA, USA
2
During a short survey in southern Sumatra, we carried out observations on the occurrence of diurnal
primates in various types of forest, their use as pets, and on the changes in the habitat. All diurnal
species distriubted in the survey area were kept, and available for sale, as pets. The majority of the
pets were infants, suggesting that most captive primates do not survive more than a few months in
captivity.
Introduction
In January 2001, we undertook a short survey of
forest of southern Sumatra in order to tape-record
calls of leaf monkeys (Trachypithecus and Presbytis)
for a comprehensive study on the radiation of the
Asian Colobines. This report summarises our observations on the occurrence of diurnal primates in
various types of forest, their use as pets, and our observations on the pet market, and on the changes in
the habitat. Although this short survey by no means
can provide a comprehensive picture of the fate of
primates in southern Sumatra, we have reason to
believe that our anecdotal observations provide an
impressionistic view of this topic that nevertheless
appears to be symptomatic of what happens to
primates and their habitat in many parts of Indonesia.
Six species of nonhuman diurnal primates occur
in the area we visited. These include the long-tailed
macaque (Macaca fascicularis), the pig-tailed macaque (M. nemestrina), the silvery leaf monkey
(Trachypithecus cristatus), the Sumatran surili (Presbytis melalophos mitrata), the agile gibbon (Hylobates agilis) and the siamang (Symphalangus syndactylus). One species, the pig-tailed macaque is considered globally threatened and is listed as Vulnerable
according to the IUCN threat criteria (IUCN, 2004).
We travelled by car from Bandar Lampung and
Way Kambas National Park (Lampung province) to
Baturaja and Lahat (Sumatera Selatan province), via
Lake Ranau (on the border of Bengkulu province and
Lampung) back to Bandar Lampung. A map of the
study area and the forests we visited is shown in
Figure 1.
Pet trade
In many parts of Indonesia, primates are widely
kept as pets. In most villages and cites we passed, we
casualy asked to see captive primates, and in most
places, we were readily offered primates for sale.
Table 1 offers a summary list of the pet primates we
saw. Some of them are shown in Figures 2-4.
103o
104 o
105 o
3o
106o
Palembang
Perabumulih
4
3
Pagaralam
4o
Lahat
Sumatra
2
Baturaja
Simpang
Martapura
Muaradua
Lake
Ranau
5o
5
Simpangsender
Kotabumi
Way
Kambas
NP
1
6
Bandar
Lampung
7
Sukamargai
6o
Java
0o
7o
100o
Fig. 1. Map of southern Sumatra
showing our travel route (red line) and
survey localities (red dots): (1) Way
Kambas, (2) Bukit Pelawi, (3) Lahat
Waterfalls, (4) Gunung Kembang, (5)
Steenkool Protection Forest, (6) Pusaka
Jaya, (7) Kedaung. Inset map: location
of survey area in South-east Asia. – Die
Karte von Südsumatra zeigt unsere
Reiseroute (rote Linie) und die Orte, an
denen
wir
Freilandbeobachtungen
durchgeführt haben (rote Punkte).
Kleine Karte: Lage der untersuchten
Region in Südostasien.
©2006 Gibbon Conservation Alliance, Switzerland, www.gibbonconservation.org
Gibbon Journal Nr. 2 – 2006
19
Table 1. Pet primates observed in southern Sumatra, 19-27 January 2001. – Primaten in Gefangenschaft, angetroffen in Südsumatra, 19.-27. Januar 2001.
Baturaja
Macaca fascicularis
Lahat
s G.
Kembang
Simpang
Martapura
Muaradua
1 ad
1 juv
1
Trachypithecus cristatus
1 inf
Presbytis melalophos mitrata
2 inf
Hylobates agilis
1 inf
Symphalangus syndactylus
1 inf
1
Total
1
Macaca nemestrina
Total
Sukamargai
1
1
1 juv
1 inf
1
5
1
1 inf
3
1
3
1
10
ad = adult, juv. = juvenile, inf. = infant
Fig. 2. Pet primates in southern Sumatra. Left: siamang (Symphalangus syndactylus) in Lahat.
Photo: Robert Dallmann. Right: Pet pig-tailed macaque (Macaca nemestrina) in a small village
south of Gunung Kembang. Photo: Thomas Geissmann. – Primaten als Haustiere in Südsumatra.
Links: Siamang in Lahat; rechts: Schweinsaffe in einem kleinen Dorf südlich von Gunung
Kembang.
Although Sumatran primates are often eaten by
certain local ethnic groups (Shepherd et al., 2004),
and Lampung has bee identified as a centre for the
trade in primates (mainly long-tailed macaques)
(KSBK, 2001), those we saw were sold or kept as
pets. These primates are often captured as young by
killing the mother in order to take the infant which
stays clinging to its dead parent. Shooting the mother
often results in the death of the young if they are
mistakenly shot, or are killed when the parent falls to
the ground. Often surviving offspring are very young
and have little chance of survival (Shepherd et al.,
2004).
Only one of ten pet primates we observed was
adult. The other age classes were represented as
follows: subadult: 0, juvenile: 2, infant: 7. This age
distribution suggests that captive primates rarely
survive long enough to reach adulthood. Many may
even die before being sold on the pet market, as is
suggested by our observation that several of the
primates we were offered for sale did not appear to be
in good health and one infant Sumatran surili offered
for sale in Muaradua was nearly comatose and obviously moribund (Fig. 3, right). An agile gibbon infant
also for sale in Muaradua had its foot recently cut off,
with the wound still not having healed. These animals
probably did not survive long after we saw them.
The two species of primate that are legally
protected, i.e. the agile gibbon and the siamang, were
not less frequently encountered than the non-protected species, nor were they less openly displayed.
Gibbon Journal Nr. 2 – 2006
20
Fig. 3. A silvery leaf monkey (Trachypithecus cristatus) (left) and a dying Sumatran surili (Presbytis
melalophos mitrata, yellow colour variant) (right) are offered for sale in Muaradua. Photos: Robert
Dallmann. – Ein Silberner Haubenlangur (links) und ein sterbender Grauer Sumatra-Langur (rechts)
werden in Muaradua zum Kauf angeboten.
Data from Java, Bali and Kalimantan (Indonesian Borneo) suggest that a considerable number of
especially siamangs, agile gibbon, and Sumatran
surili find their way to the animal markets in Java.
(Note that although an even greater number of silvery
leaf monkeys, long-tailed macaques and pig-tailed
macaques are traded in these islands, because of their
wide geographical distribution, it is difficult to pinpoint the exact location from where these animals
originate). In fact, on Java, siamang, agile gibbon,
and Sumatran surili are more commonly traded than
the endemic Javan species (Javan gibbon Hylobates
moloch, ebony leaf monkey Trachypithecus auratus,
and grizzled surili Presbytis comata) (Malone et al.
2002; Nijman, 2005a, b; V. Nijman unpubl. data).
Observations on primate habitat and habitat
destruction
Fig. 4. Pet Sumatran surili (Presbytis
melalophos mitrata, grey colour variant)
kept in Sukamargai. Photo: Robert Dallmann. – Dieser Graue Sumatra-Langur
wird als Haustier in Sukamargai gehalten.
The highest density of primates was observed in
the Way Kambas National Park, one of the few remaining lowland primary forests of Sumatra. Here,
even agile gibbons (i.e. those Sumatran primates
which are most dependent on closed canopy forests
and all-year-round fuit availability) were encountered
or heard in relatively high numbers, and the related
siamangs appeared to be abundant. In selectively
logged forests, gibbons and siamang still occurred,
but in lower numbers.
Siamangs appeared to be more resistent to forest
degradation, as we encountered forests with siamangs
Gibbon Journal Nr. 2 – 2006
21
and without agile gibbons, but not the opposite. This
is not surprising considering that siamangs are able to
survive on a more folivore diet, whereas the smaller
bodied gibbons need a higher proportion of fruits in
their diet (Raemaekers, 1979; Raemaekers & Chivers,
1980).
were absent and probably extinct. No primates were
encountered in monoculture rubber plantations (Fig.
5), although a group of long-tailed macaques was observed in the periphery of one of them, suggesting
that this particular macaque species may have a
particularly high adaptive flexibility.
In small forest patches and more heavily disturbed forests, and even in extensively used rubber
plantations that still included some of the original
forest trees, leaf monkeys (Trachypithecus and Presbytis) were observed, although gibbons and siamangs
Habitat distribution and logging were observed
in virtually every forest we visited (Figures 6-7).
These also included forests like the Steenkool
Protection Forest which is legally protected (Fig. 8).
Fig. 5. Extended areas of monoculture rubber plantations near Perabumulih. No non-human
primates survive in these areas. Photo: Robert Dallmann. – Ausgedehnte Flächen von Gummiplantagen in Monokultur in der Gegend von Perabumulih. In dieser Vegetation können keine
Affenarten überleben.
Fig. 6. A recently deforested and cultivated hill near Kedaung. Photo: Thomas Geissmann. – Ein
kürzlich gerodeter und landwirtschaftlich bepflanzter Hügel bei Kedaung.
Gibbon Journal Nr. 2 – 2006
Fig. 7. A newly cleared area of former rainforest near Gunung Kembang. Photo: Thomas Geissmann. – Frisch gerodeter ehemaliger Regenwald bei Gunung Kembang.
Fig. 8. The process of deforestation: Only small patches of forest still remain in the valley of Steenkool Protection Forest (left). These forest patches still support isolated groups of agile gibbons,
siamangs, and Sumatran surilis. The first hill chain (visible in the background) is nearly deforested,
and logging has already begun in the valley behind the hill chain. Right: Timber wood is constantly
being extracted from Steenkool Protection Forest (right). Photos: Robert Dallmann. – Der Entwaldungsprozess: Nur noch kleine Waldreste verbleiben im Tal des Steenkool Schutzwaldes
(links). In diesen leben immer noch isolierte Gruppen von Schwarzhandgibbons, Siamangs und
graue Sumatra-Languren. Der erste Hügelzug im Hintergrund ist schon fast vollständig entwaldet,
und der Holzeinschlag im dahinterliegenden Tal hat bereits begonnen. Holz wird ständig aus dem
Steenkool Schutzwald herausgetragen (rechts).
22
Gibbon Journal Nr. 2 – 2006
Discussion
Since Indonesia’s transition from the autocracy
of Soeharto to a democracy, illegal logging has
accelerated, and in large parts of the country, forest is
being lost at an alarming rate. This puts the survival
of those species that fully depend on forest at risk,
including all species of gibbons and most species of
primates. Trade in these species, and the associated
loss of individuals in the process of capturing and
trade, may exacerbate these risks (Nijman, 2005a).
Although our survey was short in duration, and
covered only the southernmost provinces of Sumatra,
we are confident that what we observed can be considered representative for what is happening throughout Sumatra, and indeed other Indonesian islands.
Habitat loss, and in particular the loss of lowland
forest, has denuded large parts of Sumatra of its wildlife. In recent years, the area of lowland forest has
seen a dramatic reduction largely due to illegal
logging (Whitten et al., 2000). Consequently, populations of especially forest-dependant species such as
the agile gibbon, siamang, and Sumatran surili must
have seen an equal reduction, although little data are
available.
In most of the villages, (pet-)primates were
openly displayed or were shown to us without hesitation. This included those species that are legally
protected by Indonesian law, suggesting that there is
a general lack of law enforcement in southern
Sumatra with respect to the protection of primates.
Indeed, data from other parts of Indonesia suggest
that few traders or owners of primates have been prosecuted for selling or keeping legally protected
primates (Nijman 2005 a, b).
If primates are to survive in the relatively
densely populated southern parts of Sumatra, both the
local and national governments have to realise that
both their habitats and the primates themselves need
to be protected to a much higher degree than observed during our survey. Trade in primates, and
keeping them as pets, needs to be discouraged much
more than at present, and both protected and non-protected forest need to be managed in a more sustainable manner.
References
IUCN (2004). 2004 IUCN Red list of threatened
species. Downloaded from www.iucnredlist.org
on 28 March 2006.
KSBK (2001). Dibalik perdagangan dagin primata di
Lampung, Sumatera. [Altering the trade in
primate meat in Lampung Sumatra]. Konservasi
Satwa bagi Kehidupan, Malang.
Malone, N., Purnama, A. R., Wedana, M., and
Fuentes, A. (2002). Assessment of the sale of
primates at Indonesian bird markets. Asian
Primates 8(1-2): 7-11.
23
Nijman, V. (2005a). In full swing: An assessment of
trade in orang-utans and gibbons on Java and
Bali, Indonesia, TRAFFIC Southeast Asia,
Petaling Jaya, Selangor, Malaysia. vii + 49 pp.
ISBN 983-3393-00-4. Downloadable from:
www.traffic.org/publications/pubs_tsea.html
Nijman, V. (2005b) Hanging in the balance: An
assessment of trade in orang-utans and gibbons
on Kalimantan, Indonesia. TRAFFIC Southeast
Asia, Petaling Jaya, Selangor, Malaysia. viii + 44
pp. ISBN 983-3393-03-9. Downloadable from:
www.traffic.org/publications/pubs_tsea.html
Raemaekers, J. J. (1979). Ecology of sympatric
gibbons. Folia Primatologica 31: 227-245.
Raemaekers, J. J. & Chivers, D. J. (1980). Socioecology of Malayan forest primates. In Chivers,
D. J. (ed.), Malayan forest primates – Ten years'
study in tropical rain forest, Plenum Press, New
York, pp. 279-316.
Shepherd, C. R., Sukumaran, J. & Wich, S. A.
(2004). Open season: An analysis of the pet trade
in Medan, Sumatra, 1997 - 2001, TRAFFIC
Southeast Asia, Petaling Jaya, Selangor,
Malaysia. vi+60 pp. Downloadable from:
www.traffic.org/publications/pubs_tsea.html
Whitten, T., Damanik, S.J., Anwar, J. & Hisyam, N.
(2000). The ecology of Sumatra, 2nd ed. Periplus,
Singapore.
Zusammenfassung
Zum Schicksal tagaktiver Primaten in SüdSumatra
In einer kurzen Studie in Südsumatra haben wir
das Vorkommen der tagaktiven Primatenarten in verschiedenen Waldtypen, im Tierhandel und in der
Haustierhaltung sowie die Veränderung des Lebensraumes der Primaten untersucht. Sechs Arten kommen im Untersuchungsgebiet vor: der Javaneraffe
(Macaca fascicularis), der südliche Schweinsaffe
(M. nemestrina), der silberne Haubenlangur (Trachypithecus cristatus), der graue Sumatra-Langur (Presbytis melalophos mitrata), der Scharzhandgibbon
(Hylobates agilis) und der Siamang (Symphalangus
syndactylus). Alle diese Arten fanden wir auch in
Gefangenschaft, wo man sie uns ohne zu zögern
zeigte oder zum Kauf anbot. Die zwei gesetzlich geschützen Arten (der Schwarzhandgibbon und der
Siamang) wurden dabei nicht seltener angetroffen als
die nicht-geschützten Arten. Dies zeigt, dass die bestehenden Artenschutzgesetze in Südsumatra nicht
durchgesetzt werden. Tatsächlich zeigen Daten von
anderen Gebieten in Indonesien, dass Händler oder
Besitzer von gesetzlich geschützten Primaten nur
selten belangt werden. Die Mehrzahl der in Gefangenschaft gehaltenen Tiere waren Jungtiere, was
darauf schliessen lässt, dass gefangene Primaten
meist nicht länger als ein paar Monate überleben.
In allen untersuchten Waldgebieten konnten wir
den Rückgang des Waldes beobachten. Dabei rea-
Gibbon Journal Nr. 2 – 2006
gierte von den beobachteten Affenarten der Schwarzhandgibbon offenbar am empfindlichsten. Da er auf
ein geschlossenes Kronendach und ganzjährige Verfügarkeit von Früchten angewiesen ist, ist er jeweils
die erste Art, die bei Verschlechterung der Waldqualität in einem Waldgebiet ausstirbt. Seit dem
Wechsel von der autokratischen Regierung unter Präsident Soeharto zu einer demokratischeren, aber
weniger zentralistischen Regierungsform hat sich der
illegale Holzschlag in Indonesien beschleunigt und
die Wälder verschwinden in alarmierendem Tempo.
Dies gefährdet insbesondere die Tierarten, die nur im
Wald überleben können, wie die Gibbons und die
meisten anderen Primatenarten. Der Tierhandel und
der damit einhergehende Tod von Tieren, die beim
Fang und im Handel sterben, erhöhen die Bedrohung
dieser Arten zusätzlich.
Obwohl unsere Studie nur von kurzer Dauer war
und nur das südliche Sumat ra einschloss, gehen wir
davon aus, dass die von uns beobachteten Verhältnisse für Sumatra und andere indonesische Inseln
24
typisch sind. Der Habitatverlust und ganz besonders
der des Flachland-Regenwaldes, haben grosse Teile
von Sumatra seiner ursprünglichen Fauna beraubt. In
den letzten Jahren ist der Flachland-Regenwald vor
allem durch illegalen Holzschlag dramatisch zurückgegangen. Dies hat zweifellos zu einem entsprechend
drastischen Rückgang der waldbewohnenden Arten –
wie der Scharzhandgibbons, Siamangs, oder der
grauen Sumatra-Languren – geführt, obwohl dazu
wenig Zahlen vorliegen.
Wenn Primaten in den relativ dicht besiedelten
südlichen Gebieten von Sumatra überleben sollen,
müssen die lokalen wie nationalen Regierungen erkennen, dass sowohl ihre Primärwälder wie auch die
darin lebenden Arten viel effizienter geschützt
werden müssen, als dies während unserer Studie der
Fall war. Der Handel mit Affen und die Haltung von
Affen müssen viel stärker als bisher bekämpft
werden, und sowohl geschützte wie nicht-geschützte
Waldgebiete müssen in einer umweltverträglicheren
Art und Weise verwaltet werden.